Sentinel lymph node mapping of breast cancer via intradermal administration of Lymphoseek

Abstract

Lymphoseek™ is a molecular imaging agent specifically designed for sentinel lymph node (SLN) mapping. We conducted a Phase I trial which measured the injection site clearance and sentinel lymph node accumulation after a single intra-dermal injection of Lymphoseek or [ 99m Tc]sulfur colloid protocol. Ten patients with breast cancer participated in this study. Five patients received an intradermal administration of 1.0 nmole of 99m Tc-labeled Lymphoseek and five patients received an intra-dermal administration of filtered [ 99m Tc]sulfur colloid (fTcSC). Lymphoseek, exhibited a significantly (P < .001) faster injection site clearance than fTcSC. The mean Lymphoseek clearance half-time was 2.61 ± 0.72 hr compared to 24.1 ± 17.7 hr for fTcSC. The mean sentinel lymph node uptake of Lymphoseek (1.1 ± .5%), and TcSC (2.5 ± 4.9%) were statistically equivalent (P = 0.28). When an intra-dermal injection was employed, Lymphoseek demonstrated faster injection site clearance than filtered [ 99m Tc]sulfur colloid.

99mTc-Tilmanocept: A Novel Molecular Agent for Lymphatic Mapping and Sentinel Lymph Node Localization

“…Faster injection site clearance and equivalent sentinel node uptake were similarly demonstrated in another phase I trial also in breast cancer patients but with an intradermal injection technique. The intradermal injection, however, did not exhibit a faster clearance half-time than peritumoral/subdermal injection (18). A similar phase I trial by the same group, performed on melanoma patients, also found that 99m Tc-tilmanocept demonstrated faster injection site clearance and equivalent primary sentinel node uptake when compared with filtered 99m Tc-SC (7).…”

Sentinel lymph node accumulation of Lymphoseek and Tc-99m-sulfur colloid using a “2-day” protocol

“…A protocol using a single intradermal injection of Lymphoseek [12] in five breast cancer patients produced a percent-of-injected dose of 1.1±0.5% when the time interval ranged from 3.4 to 6.1 h. This was lower, but not statistically significant ( P =.76), than the 2-day protocol where the sentinel lymph node uptake was 1.5±1.7% and the time interval ranged from 19.4 to 27.1 h. Sentinel lymph node uptake of filtered TcSC [12] was 2.5±4.9% when the uptake time interval ranged from 3.5 to 7.3 h. This was lower than 3.5±3.1%, the uptake achieved by unfiltered TcSC when the uptake time interval ranged from 18.0 to 25.9 h. Although noteworthy, the increase in colloid SLN accumulation achieved by the 2-day protocol was not statistically significant. This is mainly due to the high biological variation in subject lymphatic flow and function.…”

“…This accounts for the high relative error of ±167%. The clearance rate constant of filtered TcSC [12] using the same injection protocol exhibited a mean and standard deviation of 0.029 ±0.021 h −1 . The lowered relative error of ±72% occurred because only one of five studies was assigned a zero clearance rate due to a positive slope in the time–activity curve.…”

“…Changes in clinical laboratory tests before and after administration of Lymphoseek or [ 99m Tc]sulfur colloid were conducted using the Wilcoxon rank sum. Our analysis of the clinical laboratory tests combined the 11 subjects reported here and the 10 subjects reported in an earlier study [12]. A two-tailed P value of less than .05 was considered statistically significant, with no correction made for multiple comparisons.…”

High-Resolution, Hand-Held Camera for Sentinel-Node Detection

“…9 Though radioactive colloids are the most used tracers, some researchers propose alternative radiopharmaceuticals. 10 LS is generally performed on planar views; some studies 11,12 suggest more complex LS methods, including single-photon emission computed tomography (SPECT) and triangulations. Studies on GP addressed to improve this device and to standardize its performances are also available.…”